Control systems for nuclear reactors have been known for a number of years and have been improved significantly through the use of digital computers. Such computers receive information from the nuclear reactor through sensors and signal conditioners and by applying a series of mathematical manipulations, known as the control algorithm, produce output signals which are applied to actuating systems or control devices that modify the reactivity of the nuclear reactor. Many different algorithms have been developed for the purpose of digital control and the output signals produced thereby typically consist of a combination of digital signals which cause the actuating or control device to move at some combination of acceleration, velocity and/or position to vary the reactivity of the reactor. It has been found that the resulting algorithms are typically very complex in nature, and require substantial computer time and power to implement.
Because of the foregoing, it has become desirable to develop a simple control technique (algorithm) which can incrementally change a parameter, such as the position of an actuator, by a fixed unit to incrementally change the reactivity of the nuclear reactor.